The present invention relates to the field of gun barrels for the launching of large projectiles and in particular to the field of gun barrels to be used to assist with the launching of satellites into low earth orbit.
It has long been thought possible to use large guns to assist with the launching of devices into orbit. One means of potentially accomplishing this is to use a very large gun barrel to launch a projectile, such as a rocket with a satellite payload, beyond the lower atmosphere of the earth, and then to fire the rocket so that it will cause the satellite to reach orbital velocity and subsequently enter into an orbital path. The rocket is launched to a height that is above the lower atmosphere, as it is in the lower atmosphere that most drag occurs and where most rockets use up a large quantity of their fuel. By firing the rocket in the near vacuum of the upper atmosphere, less fuel is required by the rocket to achieve orbital velocity. Since a gun barrel can be used more than once, gun launching provides an economical first stage for launching satellites. Additionally, a gun launch can be used in almost any weather condition.
Long-range artillery capable of launching projectiles a significant distance was first developed and used in WW I. For example, the Paris gun, when fired at an angle of 50 degrees, was able to send a projectile to an altitude of 43.2 km, well past the 12 km that is generally considered to be the xe2x80x9clower atmospherexe2x80x9d. The Max E gun could fire a 740 kg projectile to a maximum range of 47 km. The Paris Gun and the Max E, if fired at a 90-degree angle to the earth""s surface could have fired projectiles past the lower atmosphere. The 800 mm Gustav developed in WW II could fire a 4800 kg shell a distance of 47 km, and a 7100 kg shell a distance of 38 km.
In the early 1960""s, Gerald Bull was involved with a project called HARP, an acronym for High Altitude Research Project, which program involved the use of large guns to fire projectiles and rockets to high altitudes. The HARP program was cancelled before its goal of achieving orbital entry of a device was obtained, because the system was too expensive and the available technology would not support further research. However, altitudes of 110 miles were reached, with 400-pound projectiles.
Advances in the development of rockets, new types of rocket fuels, new propellants for artillery, and advances in the design of smaller satellites, such as nano and pico satellites, which can weigh as little at 10 ounces, now make the gun-assisted launching of orbital devices, such as satellites, possible.
One component of a gun launch apparatus for the launching of a large projectile is the gun barrel. To be able to assist in achieving orbital launching of a device, the gun barrel must be very large. Traditionally, very large gun barrels have been comprised of steel, to provide the required strength and rigidity. However, steel gun barrels of the size required for gun-assisted orbital launching are expensive to make and heavy. The weight of a large steel gun barrel is a factor that significantly interferes with the ability to move or vary the location of the gun barrel, and the latter problem limits the potential to use the same gun barrel to repeatedly launch satellites into orbit, as the barrel is always pointed to the same position.
The cost of putting a satellite into orbit is currently very high. Advances in rocket and satellite technology suggest that it is worthwhile to revisit the concept of using large guns to assist with the launching of satellites into orbit, particularly if it will lower the cost of satellite launching. One way to lower the cost is to make a gun barrel that is less expensive than a steel gun barrel.
In accordance with the above objectives, there is disclosed herein a gun barrel and for use with the launching of large projectiles, and in particular to the launching of rockets with satellite payloads. The gun barrel is less expensive to manufacture than a steel gun barrel, possibly less heavy than steel and sufficiently strong for the purposes mentioned herein, namely for the firing large projectiles. The gun barrel of this invention may also be used to launch large projectiles, such as artillery, or devices that can be used to intercept nuclear weapons.
In one embodiment, the invention is a gun barrel, with
(a) a breech end and an open end;
(b) a bore disposed between the breech end and the open end,
(c) an outer support layer on an outside surface of the gun barrel;
(d) an inner support layer lining the bore of the gun barrel, and
(e) a layer compressible material disposed between the outer support layer and inner support layer, said compressible material having a compressive strength of at least 10 mPa and having a compressive strength that is less than the than the compressive strength of one of (a) the inner support layer and (b) the outer support layer.
The breech end may be closed, or closeable, for example by use of a breech plug.
The outer support layer and the inner support layer can be comprised of a metal, such as steel. The compressible material can be concrete. Alternatively, it may be another type of compressible material with a compressive strength of greater than 10 mPa, for example a plastic material. The layer of compressible material can be reinforced.
In one embodiment, the gun barrel comprises an outer layer of steel on the outside surface of the gun barrel, an inner layer of steel lining the bore of the gun barrel, and a layer of concrete disposed between the outer layer of steel and the inner layer of steel, said concrete having a compressive strength of at least 10 mPa. The gun barrel may have a breech end that is one of either (a) closed or (b) closeable, and the second end the bore is open.
In another embodiment, the invention is a gun barrel with a breech end and an open end and a bore disposed between the breech end the open end, comprising:
(a) a breech portion made of metal, and
(b) an elongate portion adjacent to the breech portion, said elongate portion further comprising:
(i) an outer support layer on an outside surface;
(ii) an inner support layer lining the bore of the gun barrel, and
(iii) a layer compressible material disposed between the outer support layer and inner support layer, said compressible material having a compressive strength of at least 10 mPa and having a compressive strength that is less than the than the compressive strength of one of (a) the inner support layer or (b) the outer support layer.
The breech end may be closed or closeable, for example with a breech plug.